Author Affiliations: Sections of General Internal Medicine (Dr Ross) and Cardiovascular Medicine (Dr Krumholz) and Robert Wood Johnson Clinical Scholars Program (Dr Krumholz), Department of Internal Medicine, School of Medicine, Yale[[ndash]]New Haven Hospital Center for Outcomes Research and Evaluation (Drs Ross and Krumholz), and Section of Health Policy and Administration, School of Public Health (Dr Krumholz), Yale University, New Haven, Connecticut; and Western University of Health Sciences, Pomona, California, and Institute for Clinical Evaluative Sciences, University of Toronto and University Health Network, Toronto, Ontario, Canada (Dr Jackevicius). Mr Downing is a medical student at Yale University School of Medicine.

The ongoing debate concerning the efficacy of fenofibrate has overshadowed an important aspect of the drug's history: Abbott Laboratories, the maker of branded fenofibrate, has produced several bioequivalent reformulations that dominate the market, although generic fenofibrate has been available for almost a decade. This continued use of branded formulations, which cost twice as much as generic versions of fenofibrate, imposes an annual cost of approximately $700 million on the US health care system. Abbott Laboratories maintained its dominance of the fenofibrate market in part through a complex switching strategy involving the sequential launch of branded reformulations that had not been shown to be superior to the first-generation product and patent litigation that delayed the approval of generic formulations. The small differences in dose of the newer branded formulations prevented their substitution with generics of older-generation products. As soon as direct generic competition seemed likely at the new dose level, where substitution would be allowed, Abbott would launch another reformulation, and the cycle would repeat. Based on the fenofibrate example, our objective is to describe how current policy can allow pharmaceutical companies to maintain market share using reformulations of branded medications, without demonstrating the superiority of next-generation products.